• Journal of Sensor Science and Technology
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• v.18 no.3
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• pp.207-209
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• 2009

This paper describes the characteristics of poly 3C-SiC micro resonators with $3{\times}10^{17}{\sim}1{\times}10^{19}cm^{-3}$ doping concentrations. The 1.2 ${\mu}m$ thick cantilever and the 0.4 ${\mu}m$ thick doubly clamped beam resonators with different lengths were fabricated using poly 3C-SiC thin films. The characteristics of poly 3C-SiC micro resonators were evaluated by quartz and a laser vibrometer in vacuum at room temperature. The resonant frequencies of micro resonators decreased with doping concentrations owing to reduction in the Young's modulus of poly 3C-SiC thin films. It was confirmed that the resonant frequencies of poly 3C-SiC resonators are controllable by doping concentrations. Therefore, poly 3C-SiC resonators could be applied to MEMS devices and bio/chemical sensor applications.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.1056-1060
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• 1997

An optical technique to align the laser beam with the rotation axis of a cylindrical microstructure is developed for laser microfabrication. The sample surface is first set normal to the rotation axis by applying a simple reflection law of geometrical optics and then the laser beam is aligned with the rotation axis using translation stages with quadrant photodiodes. Principle and the configuration of the alignment technique are described. An application of the present technique to laser microstereolithography showed that it could be effectively used for fabrication of micro cylindrical structures.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.608-611
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• 2003

In this paper, laser direct micromaching is developed to fabricate micro patterns using UV laser ( λ$_3$= 355 nm). Experimentally, laser beam paths mainly influences the surface shape quality. Thus. we proposed laser beam path generator by extracting shape data in a blueprint worked through CAD modeler and using genetic algorithm that considers the characteristics of laser beam. The results show that various shapes of micro patterns could be manufactured using proposed method in this paper.

• Steel and Composite Structures
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• v.28 no.3
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• pp.381-388
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• 2018

In this paper, forced vibration of micro cylindrical shell reinforced by functionally graded carbon nanotubes (FG-CNTs) is presented. The structure is subjected to transverse harmonic load and modeled by beam model. The size effects are considered based on strain gradient theory containing three small scale parameters. The mixture rule is used for obtaining the effective material properties of the structure. Based on sinusoidal shear deformation theory of beam, energy method and Hamilton's principle, the motion equations are derived. Applying differential quadrature method (DQM) and Newmark method, the frequency curves of the structure are plotted. The effect of different parameters including, CNTs volume percent and distribution type, boundary conditions, size effect and length to thickness ratio on the frequency curves of the structure is studied. Numerical results indicate that the dynamic deflection of the FGX-CNT-reinforced cylindrical is lower with respect to other type of CNT distribution.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.6
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• pp.797-803
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• 2013

Recently, a number of countries are now considering the reuse of effluents from wastewater treatment for various water applications. To improve the reuse of wastewater effluent, the development of appropriate micro-pollutant removal technology is necessary. Although several researche have been studied for removing micro-pollutants in water, little study has been conducted for the removal of emerging contaminant such as antibiotic resistant genes (ARGs) by disinfection processes. Therefore, the aim of this study is to compare the capacity of disinfection technologies such as chlorination, ozone, and electron beam, for removing antibiotic resistant bacteria (ARB) and ARGs. Based on this study, better ARG removal can be achieved by ozonation and electron beam. Relatively, high CT values of chlorination or ozonation are needed to remove ARB and ARG compared to conventional pathogens.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.2 s.95
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• pp.199-205
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• 2005

The governing equations of micro double cantilever beam structures interacted by electrostatic forces are obtained employing Galerkin's method based on Euler beam theory. Variations of static and dynamic responses as well as natural frequencies are estimated for applied voltages. In particular, it is investigated how the variations of beam properties resulted by manufacturing process influence the deflections and the modal characteristics. This study can help to design MEMS structures and to predict the performances with respect to manufacturing tolerances.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.9 s.90
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• pp.846-851
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• 2004

Static and dynamic responses of micro cantilever beam structures undertaking electrostatic forces are obtained employing Galerkin's method based on Euler beam theory. Variations of static and dynamic responses as well as resonant frequencies are estimated for several sets of beam properties and applied voltages. It is shown that the applied voltage influences the deflection and the modal characteristics significantly. Such information can be usefully employed for the design of MEMS structures.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.74-75
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• 2008

This work has suggested corrugation beam as a new structure for mechanical resonators. Micro beam resonators based on 3C-SiC films which have two side corrugations along the length of beams were simulated by finite-element modeling and compared to a flat rectangular beam with the same dimension. With the dimension of $36\times12\times0.5{\mu}m^3$, the flat cantilever has resonant frequency of 746 kHz. Meanwhile, this frequency reaches 1.252 MHz with the corrugated cantilever which has the same dimension with flat type but corrugation width of $6{\mu}m$ and depth of $0.4{\mu}m$. It is expected that mechanical resonators with corrugations will be very helpful for the research of sensing devices with high-resolution, high-performance oscillators and filters in wireless communications as well as measurement in basic physics.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2001.11a
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• pp.222-225
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• 2001

Optical disk drives read information by replacing a laser beam on the disk track. As information has become larger, the more accurate position control of a laser beam is necessary. In this paper, we report the analysis and fabrication of the micro mirror for optical disk drivers. The mirror was fabricated by using MEMS technology and it's characteristics investigated. Also, electrode structure for reducing squeeze effect was discussed.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.228-229
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• 2000

1970년 Ashkin이 레이저 광압을 이용하여 수 마이크로미터 크기(micrometer sized)의 유전체를 광속의 진행 방향으로 가속시킴과 동시에 광속축(beam axis)방향으로 입자를 끌어당기는데 성공함으로써 레이저를 이용한 미세구(micro-particle) 의 포획 및 조작에 대한 연구와 실험이 시작되었다$^{[1]}$ . 이후에 많은 사람들에 의해 연구가 활발히 이루어졌으며$^{[2]~[7]}$ , 이러한 레이저를 이용한 미세구의 포획방법은 광집게(optical tweezer)로써 생물학과 물리학 분야에서의 높은 가능성 때문에 지금도 연구가 계속되고 있다. (중략)